Most studies classified participants into two groups, considering the presence or absence of exposure to maltreatment. Ten studies classified individuals in the EG according to the type of maltreatment suffered (Arata et al., 2005; Bolger et al., 1998; Kim & Cicchetti, 2004; 2010; Kinard, 1999a, 1999b; Lynch & Cicchetti, 1998; Shen, 2009; Sullivan & Knutson, 2000; Vondra et al., 1989).
As shown in Table 1, the selected studies assessed childhood maltreatment from various perspectives.
The majority of studies recruited participants in protection programs without using any specific instrument to assess maltreatment. This approach indicates that the identification of individuals in the EG groups depend on the reliability of the records of the programs.
Effect of the Exposure to Maltreatment on Self-Esteem, Social Competence, Academic Performance and Peer Relationships
Analysis of the articles in this systematic review suggests that exposure to childhood maltreatment is associated with impairment in self-esteem (Arata et al., 2005; Bolger et al., 1998; Herrenkohl et al., 2012; Hibbard et al., 1992; Kim & Cicchetti, 2004; Leeson & Nixon, 2011; Lynch & Cicchetti, 1998; Shen, 2009; Soler et al., 2012, Van Bruggen et al., 2006), social competence, relationships with peers, and academic performance (De Bellis et al., 2009; Eckenrode et al., 1993; Kaufman & Cicchetti, 1989; Kim & Cicchetti, 2010; Kinard, 1999b, 2001; Sullivan & Knutson, 2000).
Comparative studies that indicated statistically significant differences have specific methodological characteristics, such as the division of EG in individuals exposed to only one type of maltreatment and exposed to more than one type of maltreatment (poly-victims) (Soler et al., 2012) or research in a clinical sample (Leeson & Nixon, 2011).
Leeson and Nixon (2011) conducted an investigation on a clinical sample of 24 children who had been exposed to maltreatment. The CG was composed of 26 children drawn from various schools in the area.
Three of the studies reviewed, all of which conducted with children, did not find statistically significant differences between children with and without a history of maltreatment in terms of self-esteem (Hibbard et al., 1992; Kim & Cicchetti, 2004; Lynch & Cicchetti, 1998).
The severity and chronicity of exposure to maltreatment seem to affect psychological adjustment results.
Kim and Cicchetti (2004), for instance, found that self-esteem mediates the link between the quality of the mother-child relationship and the impact of maltreatment upon social functioning.
Furthermore, individuals with a history of multi-type maltreatment presented worse self-esteem than individuals who did not suffer abuse or had a history of a single type of abuse.
Participants exposed to both types of violence in childhood reported lower self-esteem than those who did not experience maltreatment, or experienced a single type of it.